Column-clamp.



l. G. ENGSTROIVI.'

COLUMN CLAMP.

APPLICATION FILI-:D IuLY. I9I4.

Lp Patented Dec. M, 1915.

JISACK G. ENGSTROM, OF MINNEAPGLIS, MINNESOTA.

COLUMN-CLAMP.

Specification of Letters Patent.

Patented Dec. llt, 1min..

Application filed July 6, 1914. Serial No. 849,107.

To all whom it may concern Be it known that lt, llsAoK G. ENesTRoM, citizen of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful'lmprovements in Column- Clamps; and l do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention has for its object to provide a column clamp, which, while of simple construction and small cost, is highly eiiicient and very convenient for 'the general purposes had in View; and, to such ends, generally stated, the invention consists of the novel construction and arrangementof parts hereinafter described and defined in the claims.

Particularly, the invention is designed, as indicated, for use as a so-called column clamp to lock together the forms within which concrete columns are molded into shape, but the invention is capable of various other analogous uses. lln the drawings the clamp is illustrated as applied to hold together a rectangular column form, and,

i for such purpose, four clamping bars, pivotally connected in pairs, are employed. When used to hold columns of other polygonal form, a number of clamping bars will be employed equal to the number of sides in the form.

In the accompanying drawings, which illustrate the improved clamp in its preferred form, like characters indicate like parts throughout the several views.

Referring to the drawings, Figure 1 is a plan view showing two complete clamps applied to a rectangularj form of knock-down construction; Fig. 2 is a. perspective view of one of the so-called clamping bar locking toggles; and Fig. 3 is a detail view in plan, on an enlarged scale, of one of said toggles applied in working position, some parts being broken away and some of the exposed parts being shown in section.

The four sides of the collapsible column form are indicated by the numeral 1. As shown, the improved clamp comprises four bars 2 and a pair of locking toggles 3. rllhe bars 2 are pivotally connected, in pairs, by rivets 4. 'llhese bars 2 areidentical, one with the other, and are preferably made from fiat straight steel, with ratchetlike teeth 5, cut

in the outer edges of their free end portions.

The bars 2 are placed around the collapsible form in rectangular arrangement with their joints at diagonally opposite corners thereof, and the free end portions of said bars are overlapped, one with the other, at the other corners of said form.

The toggles 3 are provided for locking the overlapped ends of the bars 2 together and frictionally clamping said bars around the collapsible form, for holding the same assembled. Each of these locking toggles comprises a pair of channel-shaped members 6, having at their inner ends interlapped lugs 7, pivotally connected by heavy rivets 8. The outer ends of the toggles 3 are biiurcated and the prongs thereof arranged to embrace the outwardly projecting ends of the overlapped bars 2, as best shown in Fig.

By interlapping the lugs 7, the bifurcated ends of the toggles are oifset, one from the other, a distance sufficient to bring the same into alinement with the overlapped nds of the bars 2, with which they inter- The backs of the toggles 3, at the fbifurcated ends thereof, are adapted to engage the teeth 5 as bases of resistance for Athe toggles 3 in the clamping of the bars 2 onto the collapsible form. The said backs, at their inner ends, afford stops 9, which limit the straightening movement of the toggles 3. rThese stops 9 are so located as to permit the rivets 8 to be moved past a dead center, as indicated with respect to the line Y in Fig. 3. Obviously, when the rivets 8 are moved past dead center the toggles 3 are securely locked with the teeth 5 of the bars 2. n

On one member of each toggle 3 is a pair of laterally projecting lugs 10, formed by upsetting the ends of said member. By placing a bar, such as a pinch bar, between the lugs 10, the toggles 3 maybe straightened against pressure. As shown in Fig. 1, apinch bar -Z is placed between the lugs 10 of one of the toggles 3 in a position to straighten said toggle by an outward movement on said bar. used for buckling the toggle 3 in removing the same from the bars 2.

l. A clamp ofthe kind described, comprising toothed bars, having overlapped endsa toggle, comprising a pair of channel members, having bi'furcated outer ends em- This same bar may be bracing said bars' With their backs interlocked With the teeth on said bars, and stops limiting the straightening movements of said toggles.

2. A clamp of the kind described, comprising toothed bars, having overlapped ends, a toggle comprising a pair of channel members, having interlapped lugs at their joint which offsets said members, one from the other, the outer ends of said toggles being bifurcated embracing said bars With their backs intel-locked with the teeth thereof, and stops limiting the straightening movement of said toggle.

3. A clamp of the kind described, comprising toothed bars, having overlapped ends, a toggle comprising a pair of channel members, having interlapped lugs at their joint, which offsets said members, one from the other, the outer ends of said toggles being bifurcated embracing said bars with their backs interlocked With the teeth thereof, and lugs on said toggle by which the same may be straightened against pressure.

In testimony whereof I aix my signature in presence of tvvo Witnesses.

ISACK G. ENGSTROM. Witnesses:

EMILY MAY KING, HARRY D. KILGORE. 

